This block diagram shows the overall PLC system. On the top left side, the input side is shown and on the top right side, the output module is shown. This will be covered in further detail on the next few slides. In addition, this diagram shows the digital input serialzer and the various communication interfaces used to communicate with the rest of the factory equipment. Finally, at the bottom, there is the power topology which translates the 24 VDC bus into voltages used by the circuitry on the I/O and communication modules.